How to Get Your Smart TV to Stop Spying on You

In 2011, Shazam — a company originally known for pioneering the software algorithm that can identify a piece of music after sampling a few bars — demonstrated that it could do the same thing with TV clips. The resulting technology, called automatic content recognition (ACR), was quietly added to smart TVs sometime thereafter, but it didn’t gain national recognition until 2017, when the FTC forced TV manufacturer Vizio to pay a huge fine for using it without customers’ consent.

ACR works by taking audio and visual data of what you’re watching on TV, creating a “fingerprint” or data file, and then comparing that file against a digital database of recorded works. Once it finds a match, it logs the content’s metadata (what show or movie it is, what medium you’re watching it in, information on the cast, release date, and so on), building out a profile of the viewer over time. This data can be used for a variety of purposes, including personalized recommendations, advertising campaigns, and even targeted political or health-related messaging. And sometimes, that data is sold on data-broker markets.

ACR research published in late 2024 suggests that some modern TVs activate ACR as frequently as once every 10 milliseconds, and that they upload the data profile several times per minute. You may be surprised to find that, even when you’re not using the TV’s built-in streaming apps, ACR still captures content from video game consoles, DVD players, or laptops connected via HDMI. Basically, whatever you display on the TV screen is fair game.

You might think that you can prevent the uploading of this data by simply disconnecting your smart TV from the internet. That does work — for a while. But studies show that, unless you disable ACR, many TVs will continue to record and store that data and will then upload it if you ever choose to reconnect (in order to, say, perform a needed firmware update).

If you’re not particularly guarded about your privacy, ACR might initially sound harmless. You’re going to see ads anyway, so what does it matter if they’re ads for products you’re theoretically more likely to buy? The larger concern is that it’s unclear who has access to these detailed, individualized user profiles.